The long process of transforming an idea like this into a space-faring reality got a big boost in 2010 when a panel of the National Academy of Sciences gave its highest priority to exploring exoplanets and their atmospheres in the next decade.

Copernicus and Galileo told us we were not, after all, at the center of the universe, and their ideas fathered a scientific astronomy that, four hundred years later, is allowing us to be a space-faring planet.